CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating revenues
Electric	$ 210,742	$ 202,879	$ 427,051	$ 414,403
Natural gas	19,027	16,005	67,374	59,025
Other	257	289	532	595
Total operating revenues	230,026	219,173	494,957	474,023
Operating expenses
Electric fuel and purchased power, non-affiliates	3,583	3,651	6,456	7,632
Purchased power, affiliates	101,793	96,853	208,251	205,567
Cost of natural gas sold and transported	8,563	6,465	34,550	29,883
Operating and maintenance expenses	49,210	50,516	99,072	99,135
Conservation expenses	3,177	3,094	6,231	6,160
Depreciation and amortization	27,628	23,720	54,677	48,169
Taxes (other than income taxes)	7,005	7,096	13,878	14,251
Total operating expenses	200,959	191,395	423,115	410,797
Operating income	29,067	27,778	71,842	63,226
Other income, net	83	77	329	526
Allowance for funds used during construction — equity	1,751	918	3,038	1,728
Interest charges and financing costs
Interest charges — includes other financing costs of $461, $461, $917 and $923, respectively	8,656	8,583	17,338	17,187
Allowance for funds used during construction — debt	(749)	(392)	(1,299)	(739)
Total interest charges and financing costs	7,907	8,191	16,039	16,448
Income before income taxes	22,994	20,582	59,170	49,032
Income taxes	8,753	7,957	22,510	18,776
Net income	$ 14,241	$ 12,625	$ 36,660	$ 30,256